Air carrier flight crew reported the aircraft moving forward uncommanded during pushback. Captain set parking brake.
Synopsis
Air carrier flight crew reported the aircraft moving forward uncommanded during pushback. Captain set parking brake.
Narrative
During pushback off Gate XX and after I began the engine start sequence; we had stopped and then started a creep forward. It felt like we were now being towed forward but something didn't feel right. I leaned forward to see the tug and I couldn't see the tug and I commented; I don't see the tug in front of us and we're moving." The Captain said something like; I think it's one of those smaller tugs that picks up the nose and tows us; I guess he's pulling us forward. I then noticed a ramp agent standing in front and to our left with crossed wands. Suddenly the Captain abruptly states that the tug is way to our left and he has disconnected. At the same time he said this I looked to our left and saw the tug 90 degrees of our left and I said we are moving; you need to set the brakes; just as the Captain was applying the brakes and setting the parking brake. The Captain motioned for someone to come back and plug in so he could talk to them. The Captain told the ramp agent what happened and he replied that he said he (I believe the tug driver) said he said set brakes. The Captain explained that we didn't hear him say that and that also the Captain didn't make any response that the brakes were set and nor did he tell them to disconnect the interphone. The ramp agent said "yea I had to jump out of the way because the airplane was moving." The Captain told the ramp agent to make certain the tug driver knows what he did and that he would be writing this event up.The ground crew just needed to follow standard procedures. There also didn't seem to be any urgency from the ground crew for us to stop the aircraft from moving when we shouldn't have been moving. With the aircraft moving forward unexpectedly; the ground crew should have been signaling us urgently to stop. We were never told to set the parking brake and the ground crew was never cleared to disconnect; until after the corrective discussion from the Captain."
Second reporter narrative
I was the relief pilot on this flight sitting in the observer seat during pushback. Captain had released brakes and advised our ground crew they were cleared to push and to to expect a Taxiway 1 departure. Shortly thereafter our ground crew gave us clearance to start engines and First Officer (FO) began starting both engines. Shortly after that; the aircraft stopped but the ground crew did not communicate anything to the Captain. After a long uncomfortable silence; the Captain questioned to us in the cockpit if ground would have us set brakes soon. Then Captain noted that we were moving again and that ground must be just pulling us forward a few more feet. However; looking outside Captain and both FO and I all noted that the tug was clear; and that one ground crew was in front and the other to the side of the aircraft clear while we were still moving. Captain immediately then applied the brakes and requested ground reconnect interphone to talk to them. He then advised them they had never had him set the brakes and he therefore had never given them clearance to disconnect. He told them he would write the event up and confirmed the aircraft was in a safe configuration for departure. They confirmed it was and we contacted ramp to begin our taxi to departure. The event was caused by ground crew not communicating to the Captain to set brakes or get clearance to disconnect.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.